Continuity: The shape of the first ring Randy draws on the TV screen changes from an oval to a circle and then back to an oval between takes.

Continuity: When Monk and Dr. Kroger (RIP) are in the session and Monk ask Dr. Kroger where he got his watch, Dr. Kroger puts his arm on the arm of the chair and his hand across his mouth. From the back, he has his hand on his cheek, but from the front again it is back on his mouth.

Revealing: When Monk, Natalie, and Joey are fighting on the roof, the end of the metal pipe in Joey's hand wobbles around a lot, as if the pipe is made of rubber.

Continuity: At the end, the unconscious Cousin Joey changes positions on the roof. Though no one's touched him, he somehow shifts from lying curled on his side to flat on his back.

Continuity: Monk drops the harmonica onto the coffee table, and it lands in a horizontal position. Monk doesn't touch it again, but it moves to a diagonal orientation and then back to a horizontal one between takes.

Continuity: When Monk is trying to overcome his fears with Natalie and Julie's help, the blue pillow on the couch beside him alternates from lying flat to sitting upright, without being touched, throughout the scene.

Revealing: During the fight between Max and Paulie, the stunt double for Paulie is easy to spot - he has a full head of dark hair, whereas Paulie is gray and largely bald on top.

Continuity: Gulliver makes a bet with Monk and puts $50 in bills on the bar. When Monk puts down a $50 bill to match the bet and slides it across the counter, Gulliver's money has changed positions, rotating 90 degrees without being touched.

Factual error: [SPOILER ALERT] At the end of the episode, it is revealed that the mysterious cab driver had corneal transplants to repair damage to her vision from Retinitis Pigmentosa. RP is a defect of the retina, in the back of the eye, which accumulates pigment, losing its photoreceptivity, resulting in vision loss. A corneal transplant will not restore vision to someone with RP.

Continuity: At the end, the glass of egg nog Julie and Natalie leave on the floor disappears after they stand up to talk to Monk.

Plot hole: This episode's entire story line takes place in the six days before Christmas (Dec. 19-24). "Bad Santa" is shot in the right shoulder on the 19th, sustaining a wound serious enough to require wearing a sling for the next several days. Yet at the end, a mere few days later, he's recovered enough to have a knock-down-drag-out fistfight with Monk, wielding a knife and throwing powerhouse punches with his wounded arm as though no injury had ever occurred.

Visible crew/equipment: When Monk first enters "Father's" cabin, the tip of the boom mike dips briefly into the shot at the top of the screen.

Continuity: Just after Stottlemeyer and Natalie pull up to the curb to snatch Monk off the sidewalk, the boy and girl cult members instantly switch positions between takes.

Continuity: After Dr. Kroger tosses Trudy's picture to the floor, Monk drops the book he's been holding onto the mattress and kneels to retrieve the photo. In the next shot, the book has jumped to a spot on the floor beside him.

Continuity: At the end, the grocery bags Natalie carries change shape and orientation several times during Monk's confrontation with "Father."

Continuity: One of the large safety deposit box doors is standing wide open when Monk is curled up in the vault's corner. But when the camera angle changes, the door has closed itself.

Continuity: The living statue street performer holds a water bottle in his left hand while Randy questions him. When his alarm goes off and the shot cuts, the bottle jumps to his right hand.

Continuity: The broken side mirror that a distraught Stottlemeyer finds dangling from his damaged car wasn't there when Natalie pulled up to the first crime scene. And it disappears again when Natalie runs back to the car and races off to the second crime scene.

Factual error: Monk deflects the policeman's rifle shot and the bullet hits Stottlemeyer's car. But the gun fires just as Monk pushes it aside, and the car is behind them. There's nothing that could deflect the bullet back toward them, so at that angle, there's no way the shot could have struck the car.

Continuity: The damage to Stottlemeyer's new car doesn't remain consistent from shot to shot. The dents change configuration and the angle of the torn fender also changes.